i'm hitting my head with a can of vegetable juice

This is brilliant. Pandora. It uses the Music Genome Project database that has descriptors for every musician or song you can think of [I tried Jane Siberry first, then Ben Taylor -- not megastars, but the database had them] and then pulls up songs with similar characteristics from different artists. So you can discover other breathy females you like, or guys who like acoustic with electronic undertones. Just plays like a radio station, and you can tag songs as favorites, so you can buy the CD later, or whatever.

Really clevah.